1. Field of the Invention
The present invention concerns a video signal processing method, more specifically a processing method which makes it possible to display a 4/3 format image on a 16/9 format television tube.
2. Discussion of the Background
Tubes with a 16/9 format image have only recently existed on the market. These tubes were developed for high definition applications. However, today we plan to equip televisions with this type of tube, namely television sets whose architecture was designed to be compatible with future standards. Yet, all currently broadcasted programs are in 4/3 format. To display a 4/3 format video image on a 16/9 tube, it is therefore necessary to process this image to eliminate distortion or anamorphosis problems during the display.
Different techniques have been developed to display a 4/3 image on a 16/9 format television tube. Hence, in the German P 37 22 172.8 patent application, techniques based on a combination of image vertical size variation (by changing the amplitude of the vertical deflection current) and by changing the horizontal image size with electronic means are used.